Filament-filament switching can be regulated by separation between filaments together with cargo motor number.
Filament-filament switching can be regulated by separation between filaments together with cargo motor number.
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DOI：
10.1371/journal.pone.0054298
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发表时间：
2013
期刊：
影响因子：
3.7
通讯作者：
Yu CC
中科院分区：
文献类型：
--
作者：
Erickson RP;Gross SP;Yu CC
细胞内运输如何控制在细丝之间的交叉点处货物转换的可能性还没有很好的理解。在一个假设中，货物上的一些马达连接到一个细丝上，而其他马达连接到交叉的细丝上，随后的拔河决定选择哪一个细丝。我们调查这一假设，使用3D计算机模拟，并发现，在交叉口的开关增加与货物上的电机数量，但并不强烈依赖于电机数量时，灯丝接触。因此，简单地控制货物上的活跃马达的数量不能解释体内观察，发现随着马达数量的增加，开关减少，这表明了额外的调节机制。我们使用模拟来表明，一种可能的方式来调节开关是通过同时调整包含交叉灯丝的飞机之间的间隔和货物上的活动电机的总数。因此，磁丝分离对切换的影响尚未被探索。我们发现，开关的概率随灯丝间距的增加而减小。这种影响对于只有少量发动机的货物尤其强烈。当灯丝间距增加超过电机的最大头对头距离时，沿着灯丝行走的各个电机将无法到达相交的灯丝。因此，任何切换都需要货物上的其他马达附接到相交的细丝并沿着其拖曳货物，而接合在原始细丝上的马达分离。此外，如果细丝间隔足够大，则货物可能难以沿着初始细丝前进，因为接合的马达可以在交叉细丝下方行走，但是货物本身不能装配在细丝之间。因此，货物要么完全从原始细丝分离，要么必须浸入到初始细丝的侧面，然后在交叉细丝下方通过。
How intracellular transport controls the probability that cargos switch at intersections between filaments is not well understood. In one hypothesis some motors on the cargo attach to one filament while others attach to the intersecting filament, and the ensuing tug-of-war determines which filament is chosen. We investigate this hypothesis using 3D computer simulations, and discover that switching at intersections increases with the number of motors on the cargo, but is not strongly dependent on motor number when the filaments touch. Thus, simply controlling the number of active motors on the cargo cannot account for in vivo observations that found reduced switching with increasing motor number, suggesting additional mechanisms of regulation. We use simulations to show that one possible way to regulate switching is by simultaneously adjusting the separation between planes containing the crossing filaments and the total number of active motors on the cargo. Heretofore, the effect of filament-filament separation on switching has been unexplored. We find that the switching probability decreases with increasing filament separation. This effect is particularly strong for cargos with only a modest number of motors. As the filament separation increases past the maximum head-to-head distance of the motor, individual motors walking along a filament will be unable to reach the intersecting filament. Thus, any switching requires that other motors on the cargo attach to the intersecting filament and haul the cargo along it, while motor(s) engaged on the original filament detach. Further, if the filament separation is large enough, the cargo can have difficulty proceeding along the initial filament because the engaged motors can walk underneath the intersecting filament, but the cargo itself cannot fit between the filaments. Thus, the cargo either detaches entirely from the original filament, or must dip to the side of the initial filament and then pass below the crossing filament.
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DOI：
10.1016/j.cub.2010.03.024
发表时间：
2010-04-27
期刊：
Current biology : CB
影响因子：
--
作者：
Schroeder HW 3rd;Mitchell C;Shuman H;Holzbaur EL;Goldman YE
通讯作者：
Goldman YE
影响因子：
56.9
作者：
Yildiz, A;Forkey, JN;Selvin, PR
通讯作者：
Selvin, PR
影响因子：
64.5
作者：
CHENEY, RE;OSHEA, MK;MOOSEKER, MS
通讯作者：
MOOSEKER, MS
影响因子：
4.8
作者：
ISAMBERT, H;VENIER, P;CARLIER, MF
通讯作者：
CARLIER, MF
影响因子：
7.5
作者：
Ross, Jennifer L.;Ali, M. Yusuf;Warshaw, David M.
通讯作者：
Warshaw, David M.